My first computer was an Atari ST. For fun I wrote a statistical package (Multiple Regression, Factor Analysis, etc, in Basic based on some books I found in the UC Berkeley Library (UC had these books on how to run analyses on a hand calculator!). Later I just hacked into the UC system at Evans Hall and ran their SPSS program, my first experience with UNIX. I used this to run stats for my PhD dissertation.
I remember purchasing my first color monitor, and the external singe/double disk drives..each with a separate transformer. Graphics involved piecing together bitmaps. I remember logging onto a virtual community (PARKS), where people built text-based virtual worlds, and writing little programs that allowed me to monitor peoples' "private" rooms unnoticed (except by a few other geeks also parked in the room in their "invisible" vehicles) .
Musically, the Atari did just about everything a modern computer can do, with decent compositional software and midi interfaces. I remember when the Falcon came out...a terrific upgrade that never took off, because Atari was run by a bunch of geeks that had no clue how to market (they never made it to the shelves of any major distributors, and then underpriced their own distributors so they went out of business).